Faculty of Built Environment, University of New South Wales, Sydney, NSW 2052, Australia.
Anita Lawrence Chair on High Performance Architecture, Faculty of Built Environment, University of New South Wales, Sydney, NSW 2052, Australia.
Sci Total Environ. 2020 Oct 20;740:139754. doi: 10.1016/j.scitotenv.2020.139754. Epub 2020 May 27.
Urban overheating is the most documented phenomenon of climate change, causing severe energy problems. The study aims to evaluate the mitigation potential of irrigation as a response to the urban overheating and heatwaves in large cities, using simulation-based techniques. Mesoscale simulations are conducted for a 32.5 km × 22.5 km metropolitan region of Sydney, Australia, and it is modelled based on the moderate resolution imaging spectroradiometer (MODIS) 500 m resolution land surface dataset. To better represent the Sydney metropolitan area, the New South Wales Land Zoning dataset is used to remap the land surface. The weather research forecast model (WRF) combined with the urban canopy model (UCM) is used as the simulation tool. The results show that a daily irrigation scheme results in a maximum daily temperature drop of approximately 1.3 °C and an average daily air temperature decrease close to 0.5 °C. It is also found that the cooling effect due to the additional irrigation is strongly correlated to the ambient temperature, urban fraction, and the soil moisture state before irrigation. The irrigation induced cooling effect tends to be higher in the urban areas where the soil is drier before irrigation, or in a larger portion of the area that is covered with vegetation, or where the ambient temperature is higher.
城市热岛是气候变化中最具文献记载的现象，导致了严重的能源问题。本研究旨在利用基于模拟的技术评估灌溉作为应对大城市城市热岛和热浪的缓解潜力。针对澳大利亚悉尼的一个 32.5km×22.5km 的大都市地区进行了中尺度模拟，并基于中等分辨率成像光谱仪 (MODIS) 500m 分辨率的陆地表面数据集进行建模。为了更好地代表悉尼大都市区，使用新南威尔士土地分区数据集来重新映射陆地表面。天气研究预报模型 (WRF) 与城市冠层模型 (UCM) 相结合作为模拟工具。结果表明，每日灌溉方案可使最高日温差降低约 1.3°C，平均日气温降低接近 0.5°C。还发现，由于额外灌溉而产生的冷却效果与环境温度、城市部分以及灌溉前土壤湿度状态密切相关。在灌溉前土壤较干燥、植被覆盖率较大或环境温度较高的城市地区，灌溉引起的冷却效果往往更高。
